Stoker



Dec. 20, 1949 J. s. BENNETT ET AL STOKER Filed July 20, 1946 ALLENWTHOESON After/7g] Patented Dec. 20, 1949 UNITED STATES PATENT OFFICESTOKER Application July 20, 1946, Serial No. 685,227

4 Claims. 1

This invention relates to stokers, and more particularly to stokers foruse in the larger furnace installations.

One object of the present invention is to provide generally improvedstokers, which are simple in construction and which assure maximumefficiencies.

Another object is to provide in a furnace a pair of stokers arranged inend to end relation, the adjacent ends thereof being disposed in spacedrelation within the furnace with the outer ends terminating inenclosures mounted exteriorly of the furnace, and means for dischargingthe ashes from said enclosures to a place of disposal.

A still further object is to provide in a furnace a pair of stokersarranged in end to end relation, and a wall disposed between theadjacent ends of said stokers.

A still further object is to provide in a furnace a pair of travelinggrate stokers arranged in end to end relation, and a wall consisting ofa series of fluid conducting tubes disposed between the adjacent ends ofsaid stokers.

Other and further objects will become apparent as the description of theinvention progresses.

Of the drawing The single figure is a sectional elevational view takenthrough a furnace showing a preferred arrangement of the stokerscomprising the present invention.

Referring to the drawing the numeral I33 designates generally a furnacecomprising front and rear walls I3I and i32, respectively, and sidewalls I33, only one of the latter of which being shown. The bottom ofthe furnace has provided therein a pair of stokers 134 and I35.

Inasmuch as the specific details of construction of stokers I34 and I35form no part of the present invention, only so much of the structurethereof as is necessary to an understanding of the invention will begiven herein. For a complete description of stokers of this type,reference may be had to the pending application of June E. Beck andErnst L. Midgette, Serial No. 644,580, filed January 31, 1946, forimprovements in stokers.

Stoker I34 comprises a supporting framework I36, having sprocket wheelsI31 and I38 rotatably mounted at the opposite ends thereof. The

framework I36 is supported upon transverse I-beams I39, which in turnare supported at the opposite ends thereof in side walls I33 ofthefurnace. A series of transverse grate members I40 disposed inoverlapping relation constitute the grate I 4! of the stoker. The gratemembers Hi5 are pivotally attached to chains (not shown), which in turnare trained over the sprocket wheels I31 and I38. Sprocket wheel I31 isconnected to any suitable operating mechanism which functions to actuatethe latter in such a manner as to cause the upper run of the grate Mi totravel from right to left as viewed in the figure of the accompanyingdrawing. The front end of the stoker 34 extends into an enclosure I42,mounted exteriorly of front wall I3I. An ash pocket I43 is disposedbeneath enclosure I42 and receives the ashes which are dumped over theleft hand end of stoker I34.

Fuel is fed to stoker I34 through an opening I44 provided in front wallI3I by a feeding and distributing rotor I45. Fuel from a hopper I45 isconveyed to rotor I45 by conveyor I41. The siftings passing between thegrates I40 of stoker I34 gravitate into a hopper I43, which in turn isconnected to a spout I49 which conducts them to a place of disposal.

Air for combustion enters the chamber I50 disposed beneath stoker I34through an opening I5I, the air being supplied under pressure by anysuitable fan or blower mechanism (not shown).

Stoker I35 is similar in construction to stoker I34 and also comprises asupporting framework I52, having sprocket wheels I 53 and I54 rotatablymounted at the opposite ends thereof. Framework I52 is supported upon aseries of transverse I-beams I55, which in turn are supported at theiropposite ends in side walls I33 of the furnace.

The grate I56 of stoker I35 is comprised of a series of transverse gratebars I51 disposed in overlapping relation. Grate bars I51 are pivotallyattached to chains (not shown), which in turn are trained over sprocketwheels I53 and I54. Sprocket wheel I54 is actuated by any suitable powermechanism (not shown), the operation thereof being such as to cause theupper run of grate I56 to travel from left to right of the furnace asviewed in the figure of the accompanying drawing. The right hand end ofstoker I35 as viewed in said figure, extends into an enclosure I58mounted exteriorly of rear wall I32.

A hopper 1159 is disposed beneath extension I58 and receives the ashesdischarging over the right hand end of stoker I35.

Fuel is fed to stoker I35 through an opening i813 provided in rear wallI32 by a feeding and distributing rotor I6I. Fuel from a hopper I62 isconducted to the rotor MI by a conveyor I63. Siftings passing betweenthe grates I51 of stoker I gravitate into a hopper I84 disposed beneathstoker I35, which in turn is connected to a spout I65 which conductsthem to a place of disposal.

Air for combustion is introduced into a chamber I66 disposed beneathstoker I35 through an opening I61 provided in the side wall I33 of thefurnace, the :air being supplied thereto under pressure by any suitablefan or blower mechanism (not shown).

The inner ends I10 and "I of stokers I34 and I35, respectively, arespaced slightly apart. A central wall I12 extends vertically between theinner ends I10 and Ill of .stokers I34 and I35, respectively. Wall I12extends transversely between the side Walls I33 of the furnace and:comprises a series of vertically disposed fluid conducting tubes I13.The lower ends of tubes I13 are connected to a transverse header I14,which in turn is connected to a boiler (not shown") by downtakeconnections I15. The intermediate portions I :16 .of the tubes I13extend between the end walls I11 and I18 of the chambers I58 and I56,respectively, which chambers are disposed beneath the stokers I34 andI-35, respectively. The end walls I 11 and I18 are supported upon andsecured to transverse beams I19 and I80, and

the upper ends thereof are curved as shown at I'8I and I82, so as toextend around a portion of the inner ends I10 and I1] of the stokers I34and I35, respectively. The curved portions lI8I and I82 have removablyattached to the upper ends thereof sealing plates I83 and I84, Whichengage the .upper ends of the grate bars I40 and I51 of stokers I34 andI35, .as they pass over the inwardly disposed sprocket wlheels I38 andI54, respectively. Curved portions I8I and I82 have extending inwardlyand upwardly from the upper- .ends thereof extensions I85 and I85, theupper ends of which respectively engage the protective blocks I81 andI88 provided at the opposite sides of tubes I13. Curved portions I84 andI82 are provided with air openings I89 and I90 through which air fromthe chambers I50 and I 6.8 disposed beneath the s-tokers may enter thechambers defined by the said curved portions I8I and I82 and theupwardly inclined extensions I85 .and and I06. The air entering saidchambers is discharged therefrom through openings I91 and 192 providedin inclined extensions I85 and 185, respectively. The air thus not onlycools the inclined extensions I85 and I86 but enters the combustionchamber of the furnace as secondary air to effect burning of the fueland gas contained therein. The upper ends of the tubes I13 may beconnected to the boiler (not shown).

Sealing plates I 04 and I 95 are provided near the front ends of stokersI34 and I35, respectively, whereby the flow of combustion air isconfined between the grate members disposed between the-inner ends ofsealing plates I83, I94 and I84, I95, respectively.

From the foregoing description it is seen that the construction shown inthe drawing is especially adapted for large furnace installations, awall comprising fluid conducting tubes being disposed between thestokers. Inasmuch as the fluid cooled wall I12 is connected to theboiler, the presence thereof in the .furnace adds to the capacity of theboiler and also causes a more complete absorption of the heat generatedin the furnace. The construction is also of a simplified nature and iscapable of operating at the highest efliciencies.

While the embodiment herein shown and described is admirably adapted tofulfill the objects primarily stated, it is to be understood that it isnot intended to limit the invention thereto, since it may be embodied inother forms, all coming within the scope of the claims which follow.

What is claimed is:

1. In a device of the class described, the combination of a furnacecomprising front, rear and side walls, a traveling grate stokerextending into said furnace from said front wall, a second stokerextending into said furnace from said rear wall, an air chamber beneatheach of the stokers, said chambers having inner confronting, relativelyspaced walls, a series of upright fluid conducting tubes extendingupwardly between the said confronting walls of the air chambers andforming elements of a wall structure between and in close proximately tothe inner ends of the stokers, and a fluid supply header connected tothe ends of said tubes.

2. A device according to claim 1 wherein the said inner confrontingwalls of the air chamber are extended upwardly above the inner ends ofthe stokers to form chambers at the respective sides of the tubular wallhaving ports communicating with the respective air chambers beneath thestokers and also with the combustion spaces above the stokers.

3. A device according to claim 2 wherein a sealing plate for the innerend of the adjacent stoker is anchored on each of the upward extensionsof the said inner confronting Walls of the air chambers.

4. In a device of the class described, the combination of a furnacecomprising front, rear and side walls, a substantially horizontallydisposed endless traveling grate stoker extending into said furnace fromsaid front wall, a second substantially horizontally disposed endlesstraveling .gr-a'te stoker extending into said furnace from said rearwall, a wall comprising a series of upright fluid conducting tubesextending upwardly between and in close proximity to the inner ends ofsaid stokers, means for sealing the spaces between the inner ends of thestokers and said wall so as to prevent escape of fuel at the said innerends, ash pockets at the outer ends of said stokers, and means at saidfront and rear furnace walls respectively for feeding and distributingfuel over the adjoining stokers.

JOSEPH .S. BENNETT. ALLEN W. THORSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 608,065 Moore July 26, 1898984,197 C-rowe Feb. 14, 1911 1,051,890 Jacobus Feb. 4, 1913 1,120,254Vallino Dec. 8, 1914 1,198,841 Hand Sept. 19, 1916 1,878,524 JohnsonSept. 20, 1932 2,057,622 Webster et al. Oct. 13, 1936 2,302,173 BeersNov. 1'7, 1942 FOREIGN PATENTS Number Country Date 554,223 Great BritainJune 24, 1943

